A 9-year-old boy died and his 10-year-old sister is in critical condition after carbon monoxide leaked into their bedroom at a New Jersey home Tuesday morning, authorities said.
The house was equipped with a carbon monoxide detector, but the device's batteries were dead, police said.
The boy was pronounced dead shortly after the incident at the home on Passaic Avenue in Linden, according to authorities. The girl was taken to Newark Beth Israel Medical Center and was set to be transferred to Jacobi Hospital for specialized treatment.
Their mother, who wasn't injured, called police to report that one of the two children was having difficulty breathing. She had administered CPR to the boy before an ambulance arrived, police said.
The incident remained under investigation, but authorities say that a malfunctioning furnace or burner might have caused carbon monoxide to leak into the basement and the children's room above it.
Neighbor Arlene Carolina said that the siblings' mother was a nurse and that she used to babysit the pair.
"She's a very good mother, a very good mother," Carolina said.
The Linden Fire Department and the Red Cross offered free smoke and carbon monoxide detectors two weeks ago, but no one from the household called back to receive one, police said.